CEH describes SQL injection testing as a core part of web application assessment. One of the first and safest validation techniques is using a tautology-based SQL injection payload, such as ' OR ' 1 ' = ' 1. If the application concatenates user input directly into SQL queries, such an input will cause the query to always evaluate as true, often returning additional records such as multiple user profiles. This confirms the presence of SQL injection without causing destructive effects like dropping tables. Testing XSS does not validate SQL injection, brute-forcing credentials is unrelated, and directory traversal attacks target file path manipulation rather than backend queries. CEH emphasizes avoiding destructive queries and starting with non-intrusive injection payloads that reveal improper input sanitization, making ' OR ' 1 ' = ' 1 the correct technique for confirming SQL injection vulnerabilities in URL parameters.